Volunteers work to make conditions at Kentucky's Saltpetre Cave more amenable to endangered Indiana bats © Jim Kennedy, BCI

Protecting Endangered Cave Bats

SALTPETRE CAVE, Kentucky - Little by little, a Kentucky cave that once was a popular hibernation home endangered Indiana bats, is being restored to its original condition - or even better, at least as far as the bats are concerned. The bats are beginning to return, reports the The Daily Independent newspaper of Ashland, Kentucky Jim Kennedy, Bat Conservation International's cave resources specialist, described the situation recently as he led wildlife professionals and volunteer cavers along a narrow, tube-like passage of Saltpetre Cave. Also on the trip was Daily Independent reporter Allen Blair. Kennedy and his colleagues, the newspaper said, were wending their way through the cave as part of continuing restoration efforts designed to increase the population of Indiana bats that hibernate each winter in Saltpetre Cave. In 1998, BCI initiated a long-term research project, which included federal wildlife researchers, the Kentucky Department of Fish and Wildlife Resources and other agencies, on the winter cave homes of the Indiana bat. They have now documented the microclimates of 25 of the most important hibernation caves in six states, including Saltpetre. Kennedy said the research shows that very few caves provide the ideal cold and stable temperatures needed by the hibernating bats, which require particularly cold caves and are very susceptible to disturbance. Saltpetre cave was mined as early as 1812 for saltpeter, once a key ingredient in gunpowder. Tourism eventually took center stage, the newspaper said, as landowners strung electric lights through the cave. The Kentucky state parks system bought the cave in 1946. Its entrance now includes a concrete stairway. On this trip, the newspaper said, Kennedy and another researcher placed temperature-sensing “dataloggers” in the cave to monitor temperature ranges. They also found many “roost stains” that had not been documented earlier. The stains - caused by centuries of body oils and excrement from roosting bats - suggest Saltpetre was home to as many as half a million Indiana bats before settlers came. “All along the ledges where you would expect bats to roost, they roosted,” he told the newspaper. “Every little ledge and ceiling pocket.” “It's forensics,” Kennedy continued. “We look at the evidence and say, 'This was once a bat cave, now what can we do to get bats to use it again.' We have done a lot of things that make the species suffer. Now we're using our technology and wisdom to undo some of those things.” The park agreed several years ago to cut its winter tours and close the cave during the bats' winter hibernation time. The Indiana bat count promptly began increasing: From a few dozen in the 1980s, Kennedy's data show, the population grew to 475 in 1999, about 1,200 in 2001, and 3,100 this year. Besides removing the human disturbance, Kennedy and the others have tracked air flow and found ways to improve it for the bats. The Daily Independent notes that on this trip, Kennedy and the cavers cleaned out several sinkhole entrances and enlarged a passage near the stairs, built a door, and redirected air flow into the cave. The goal is to get more cold winter air into the cave and keep it there longer, thereby lowering the cave's temperature by at least 2 degrees Celsius, bringing conditions closer to what Indiana bats prefer for hibernation.

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